[cc] Store CCLayerImpls as scoped_ptrs

cc/IOSurfaceLayerChromium.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 #ifndef IOSurfaceLayerChromium_h
 #define IOSurfaceLayerChromium_h
 
 #if USE(ACCELERATED_COMPOSITING)
 
 #include "LayerChromium.h"
 
 namespace cc {
 
 class IOSurfaceLayerChromium : public LayerChromium {
 public:
     static scoped_refptr<IOSurfaceLayerChromium> create();
 
     void setIOSurfaceProperties(uint32_t ioSurfaceId, const IntSize&);
 
-    virtual PassOwnPtr<CCLayerImpl> createCCLayerImpl() OVERRIDE;
+    virtual scoped_ptr<CCLayerImpl> createCCLayerImpl() OVERRIDE;
     virtual bool drawsContent() const OVERRIDE;
     virtual void pushPropertiesTo(CCLayerImpl*) OVERRIDE;
 
 protected:
     IOSurfaceLayerChromium();
 
 private:
     virtual ~IOSurfaceLayerChromium();
 
     uint32_t m_ioSurfaceId;
     IntSize m_ioSurfaceSize;
 };
 
 }
 #endif // USE(ACCELERATED_COMPOSITING)
 
 #endif